Pub/sub brokers - AWS SNS/SQS - 《Dapr v1.9 Documentation》

AWS SNS/SQS
- Component format
  - Warning
Spec metadata fields
- Additional info
Create an SNS/SQS instance
Related links

Detailed documentation on the AWS SNS/SQS pubsub component

Component format

To setup AWS SNS/SQS for pub/sub, create a component of type pubsub.snssqs. Learn more on how to create and apply a pubsub configuration.

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: snssqs-pubsub
spec:
  type: pubsub.snssqs
  version: v1
  metadata:
    - name: accessKey
      value: "AKIAIOSFODNN7EXAMPLE"
    - name: secretKey
      value: "wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY"
    - name: region
      value: "us-east-1"
    # - name: endpoint # Optional. 
    #   value: "http://localhost:4566"
    # - name: sessionToken  # Optional (mandatory if using AssignedRole, i.e. temporary accessKey and secretKey)
    #   value: "TOKEN"
    # - name: messageVisibilityTimeout # Optional
    #   value: 10
    # - name: messageRetryLimit # Optional
    #   value: 10
    # - name: messageReceiveLimit # Optional
    #   value: 10
    # - name: sqsDeadLettersQueueName # Optional
    # - value: "myapp-dlq"
    # - name: messageWaitTimeSeconds # Optional
    #   value: 1
    # - name: messageMaxNumber # Optional
    #   value: 10
    # - name: fifo # Optional
    #   value: "true"
    # - name: fifoMessageGroupID # Optional
    #   value: "app1-mgi"
    # - name: disableEntityManagement # Optional
    #   value: "false"
    # - name: disableDeleteOnRetryLimit # Optional
    #   value: "false"
    # - name: assetsManagementTimeoutSeconds # Optional
    #   value: 5
    # - name: concurrencyMode # Optional
    #   value: "single"

Warning

The above example uses secrets as plain strings. It is recommended to use [a secret store for the secrets]](https://docs.dapr.io/operations/components/component-secrets/)).

Spec metadata fields

Field	Required	Details	Example
accessKey	Y	ID of the AWS account/role with appropriate permissions to SNS and SQS (see below)	`“AKIAIOSFODNN7EXAMPLE”`
secretKey	Y	Secret for the AWS user/role. If using an `AssumeRole` access, you will also need to provide a `sessionToken`	`“wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY”`
region	Y	The AWS region where the SNS/SQS assets are located or be created in. See this page for valid regions. Ensure that SNS and SQS are available in that region	`“us-east-1”`
endpoint	N	AWS endpoint for the component to use. Only used for local development with, for example, localstack. The `endpoint` is unncessary when running against production AWS	`“http://localhost:4566“`
sessionToken	N	AWS session token to use. A session token is only required if you are using temporary security credentials	`“TOKEN”`
messageReceiveLimit	N	Number of times a message is received, after processing of that message fails, that once reached, results in removing of that message from the queue. If `sqsDeadLettersQueueName` is specified, `messageReceiveLimit` is the number of times a message is received, after processing of that message fails, that once reached, results in moving of the message to the SQS dead-letters queue. Default: `10`	`10`
sqsDeadLettersQueueName	N	Name of the dead letters queue for this application	`“myapp-dlq”`
messageVisibilityTimeout	N	Amount of time in seconds that a message is hidden from receive requests after it is sent to a subscriber. Default: `10`	`10`
messageRetryLimit	N	Number of times to resend a message after processing of that message fails before removing that message from the queue. Default: `10`	`10`
messageWaitTimeSeconds	N	The duration (in seconds) for which the call waits for a message to arrive in the queue before returning. If a message is available, the call returns sooner than `messageWaitTimeSeconds`. If no messages are available and the wait time expires, the call returns successfully with an empty list of messages. Default: `1`	`1`
messageMaxNumber	N	Maximum number of messages to receive from the queue at a time. Default: `10`, Maximum: `10`	`10`
fifo	N	Use SQS FIFO queue to provide message ordering and deduplication. Default: `“false”`. See further details about SQS FIFO	`“true”`, `“false”`
fifoMessageGroupID	N	If `fifo` is enabled, instructs Dapr to use a custom Message Group ID for the pubsub deployment. This is not mandatory as Dapr creates a custom Message Group ID for each producer, thus ensuring ordering of messages per a Dapr producer. Default: `“”`	`“app1-mgi”`
disableEntityManagement	N	When set to true, SNS topics, SQS queues and the SQS subscriptions to SNS do not get created automatically. Default: `“false”`	`“true”`, `“false”`
disableDeleteOnRetryLimit	N	When set to true, after retrying and failing of `messageRetryLimit` times processing a message, reset the message visibility timeout so that other consumers can try processing, instead of deleting the message from SQS (the default behvior). Default: `“false”`	`“true”`, `“false”`
assetsManagementTimeoutSeconds	N	Amount of time in seconds, for an AWS asset management operation, before it times out and cancelled. Asset management operations are any operations performed on STS, SNS and SQS, except message publish and consume operations that implement the default Dapr component retry behavior. The value can be set to any non-negative float/integer. Default: `5`	`0.5`, `10`
concurrencyMode	N	When messages are received in bulk from SQS, call the subscriber sequentially (“single” message at a time), or concurrently (in “parallel”). Default: `“parallel”`	`“single”`, `“parallel”`

Additional info

Conforming with AWS specifications

Dapr created SNS topic and SQS queue names conform with AWS specifications. By default, Dapr creates an SQS queue name based on the consumer app-id, therefore Dapr might perform name standardization to meet with AWS specifications.

When the pub/sub SNS/SQS component provisions SNS topics, the SQS queues and the subscription behave differently in situations where the component is operating on behalf of a message producer (with no subscriber app deployed), than in situations where a subscriber app is present (with no publisher deployed).

Due to how SNS works without SQS subscription in publisher only setup, the SQS queues and the subscription behave as a “classic” pub/sub system that relies on subscribers listening to topic messages. Without those subscribers, messages:

Cannot be passed onwards and are effectively dropped
Are not available for future subscribers (no replay of message when the subscriber finally subscribes)

SQS FIFO

Using SQS FIFO (fifo metadata field set to "true") per AWS specifications provides message ordering and deduplication, but incurs a lower SQS processing throughput, among other caveats.

Specifying fifoMessageGroupID limits the number of concurrent consumers of the FIFO queue used to only one but guarantees global ordering of messages published by the app’s Dapr sidecars. See this AWS blog post to better understand the topic of Message Group IDs and FIFO queues.

Default parallel `concurrencyMode`

Since v1.8.0, the component supports the "parallel" concurrencyMode as its default mode. In prior versions, the component default behavior was calling the subscriber a single message at a time and waiting for its response.

Important

When running the Dapr sidecar (daprd) with your application on EKS (AWS Kubernetes) node/pod already attached to an IAM policy defining access to AWS resources, you must not provide AWS access-key, secret-key, and tokens in the definition of the component spec.

Self-Hosted
Kubernetes
AWS

For local development, the localstack project is used to integrate AWS SNS/SQS. Follow these instructions to run localstack.

To run localstack locally from the command line using Docker, apply the following cmd:

docker run --rm -it -p 4566:4566 -p 4571:4571 -e SERVICES="sts,sns,sqs" -e AWS_DEFAULT_REGION="us-east-1" localstack/localstack

In order to use localstack with your pub/sub binding, you need to provide the endpoint configuration in the component metadata. The endpoint is unnecessary when running against production AWS.

See Authenticating to AWS for information about authentication-related attributes.

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: snssqs-pubsub
spec:
  type: pubsub.snssqs
  version: v1
  metadata:
    - name: accessKey
      value: "anyString"
    - name: secretKey
      value: "anyString"
    - name: endpoint
      value: http://localhost:4566
    # Use us-east-1 or any other region if provided to localstack as defined by "AWS_DEFAULT_REGION" envvar
    - name: region
      value: us-east-1

To run localstack on Kubernetes, you can apply the configuration below. Localstack is then reachable at the DNS name http://localstack.default.svc.cluster.local:4566 (assuming this was applied to the default namespace), which should be used as the endpoint.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: localstack
spec:
  # using the selector, we will expose the running deployments
  # this is how Kubernetes knows, that a given service belongs to a deployment
  selector:
    matchLabels:
      app: localstack
  replicas: 1
  template:
    metadata:
      labels:
        app: localstack
    spec:
      containers:
      - name: localstack
        image: localstack/localstack:latest
        ports:
          # Expose the edge endpoint
          - containerPort: 4566
---
kind: Service
apiVersion: v1
metadata:
  name: localstack
  labels:
    app: localstack
spec:
  selector:
    app: localstack
  ports:
  - protocol: TCP
    port: 4566
    targetPort: 4566
  type: LoadBalancer

In order to run in AWS, create or assign an IAM user with permissions to the SNS and SQS services, with a policy like:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "YOUR_POLICY_NAME",
      "Effect": "Allow",
      "Action": [
        "sns:CreateTopic",
        "sns:GetTopicAttributes",
        "sns:ListSubscriptionsByTopic",
        "sns:Publish",
        "sns:Subscribe",
        "sns:TagResource",
        "sqs:ChangeMessageVisibility",
        "sqs:CreateQueue",
        "sqs:DeleteMessage",
        "sqs:GetQueueAttributes",
        "sqs:GetQueueUrl",
        "sqs:ReceiveMessage",
        "sqs:SetQueueAttributes",
        "sqs:TagQueue"
      ],
      "Resource": [
        "arn:aws:sns:AWS_REGION:AWS_ACCOUNT_ID:*",
        "arn:aws:sqs:AWS_REGION:AWS_ACCOUNT_ID:*"
      ]
    }
  ]
}

Plug the AWS account ID and AWS account secret into the accessKey and secretKey in the component metadata, using Kubernetes secrets and secretKeyRef.

Alternatively, let’s say you want to provision the SNS and SQS assets using your own tool of choice (e.g. Terraform) while preventing Dapr from doing so dynamically. You need to enable disableEntityManagement and assign your Dapr-using application with an IAM Role, with a policy like:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "YOUR_POLICY_NAME",
      "Effect": "Allow",
      "Action": [
        "sqs:DeleteMessage",
        "sqs:ReceiveMessage",
        "sqs:ChangeMessageVisibility",
        "sqs:GetQueueUrl",
        "sqs:GetQueueAttributes",
        "sns:Publish",
        "sns:ListSubscriptionsByTopic",
        "sns:GetTopicAttributes"
      ],
      "Resource": [
        "arn:aws:sns:AWS_REGION:AWS_ACCOUNT_ID:APP_TOPIC_NAME",
        "arn:aws:sqs:AWS_REGION:AWS_ACCOUNT_ID:APP_ID"
      ]
    }
  ]
}